CVE-2026-9545

EUVD-2026-41493
In this scenario, libcurl first uses a proper HTTP/3 server for the initial
transfers, and when it makes a second transfer to the same site it has been
replaced by the attacker's impostor machine - without a valid certificate.

When libcurl returns to the hostname the second time with a cached SSL session
(`CURLOPT_SSL_SESSIONID_CACHE` is not disabled) and early data enabled (the
`CURLSSLOPT_EARLYDATA` bit is set in `CURLOPT_SSL_OPTIONS`), libcurl might
send off the second request's bytes on that new connection *before* enforcing
the certificate verification failure. Potentially leaking sensitive
information.
ProviderTypeBase ScoreAtk. VectorAtk. ComplexityPriv. RequiredVector
curlCNA
7.5 HIGH
NETWORK
LOW
NONE
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N
Base Score
CVSS 3.x
EPSS Score
Percentile: 32.65%
Affected Products (NVD)
VendorProductVersion
haxxcurl
8.11.0 ≤
𝑥
< 8.21.0
𝑥
= Vulnerable software versions
Early Detection
Affected products identified ahead of NVD analysis through intelligence sources.
VendorProductVersionSource
curlcurl
8.11.0 ≤
𝑥
< 8.14.2
CNA
curlcurl
8.15.0 ≤
𝑥
< 8.16.1
CNA
curlcurl
8.17.0 ≤
𝑥
< 8.20.1
CNA
curlcurl
8.20.0
CNA
curlcurl
8.19.0
CNA
curlcurl
8.18.0
CNA
curlcurl
8.17.0
CNA
curlcurl
8.16.0
CNA
curlcurl
8.15.0
CNA
curlcurl
8.14.1
CNA
curlcurl
8.14.0
CNA
curlcurl
8.13.0
CNA
curlcurl
8.12.1
CNA
curlcurl
8.12.0
CNA
curlcurl
8.11.1
CNA
curlcurl
8.11.0
CNA
Debian logo
Debian Releases
Debian Product
Codename
curl
bookworm
7.88.1-10+deb12u15
fixed
bookworm (security)
7.88.1-10+deb12u5
fixed
bullseye
not-affected
forky
8.22.0-1
fixed
sid
8.23.0~rc2-1
fixed
trixie
no-dsa
Ubuntu logo
Ubuntu Releases
Ubuntu Product
Codename
curl
bionic
not-affected
focal
not-affected
jammy
not-affected
noble
not-affected
questing
Fixed 8.14.1-2ubuntu1.4
released
resolute
Fixed 8.18.0-1ubuntu2.2
released
trusty
not-affected
xenial
not-affected
openSUSE logo
openSUSE / SLES Releases
openSUSE Product
Release
curl
suse enterprise desktop 15 SP7
8.14.1-150700.7.20.1
fixed
suse enterprise sap 15 SP4
8.14.1-150400.5.86.1
fixed
suse enterprise sap 15 SP5
8.14.1-150400.5.86.1
fixed
suse enterprise sap 15 SP6
8.14.1-150600.4.46.1
fixed
suse enterprise sap 15 SP7
8.14.1-150700.7.20.1
fixed
suse enterprise server 15 SP4
8.14.1-150400.5.86.1
fixed
suse enterprise server 15 SP5
8.14.1-150400.5.86.1
fixed
suse enterprise server 15 SP6
8.14.1-150600.4.46.1
fixed
suse enterprise server 15 SP7
8.14.1-150700.7.20.1
fixed
libcurl-devel
suse enterprise desktop 15 SP7
8.14.1-150700.7.20.1
fixed
suse enterprise sap 15 SP4
8.14.1-150400.5.86.1
fixed
suse enterprise sap 15 SP5
8.14.1-150400.5.86.1
fixed
suse enterprise sap 15 SP6
8.14.1-150600.4.46.1
fixed
suse enterprise sap 15 SP7
8.14.1-150700.7.20.1
fixed
suse enterprise server 15 SP4
8.14.1-150400.5.86.1
fixed
suse enterprise server 15 SP5
8.14.1-150400.5.86.1
fixed
suse enterprise server 15 SP6
8.14.1-150600.4.46.1
fixed
suse enterprise server 15 SP7
8.14.1-150700.7.20.1
fixed
libcurl4
suse enterprise desktop 15 SP7
8.14.1-150700.7.20.1
fixed
suse enterprise sap 15 SP4
8.14.1-150400.5.86.1
fixed
suse enterprise sap 15 SP5
8.14.1-150400.5.86.1
fixed
suse enterprise sap 15 SP6
8.14.1-150600.4.46.1
fixed
suse enterprise sap 15 SP7
8.14.1-150700.7.20.1
fixed
suse enterprise server 15 SP4
8.14.1-150400.5.86.1
fixed
suse enterprise server 15 SP5
8.14.1-150400.5.86.1
fixed
suse enterprise server 15 SP6
8.14.1-150600.4.46.1
fixed
suse enterprise server 15 SP7
8.14.1-150700.7.20.1
fixed
libcurl4-32bit
suse enterprise desktop 15 SP7
8.14.1-150700.7.20.1
fixed
suse enterprise sap 15 SP4
8.14.1-150400.5.86.1
fixed
suse enterprise sap 15 SP5
8.14.1-150400.5.86.1
fixed
suse enterprise sap 15 SP6
8.14.1-150600.4.46.1
fixed
suse enterprise sap 15 SP7
8.14.1-150700.7.20.1
fixed
suse enterprise server 15 SP4
8.14.1-150400.5.86.1
fixed
suse enterprise server 15 SP5
8.14.1-150400.5.86.1
fixed
suse enterprise server 15 SP6
8.14.1-150600.4.46.1
fixed
suse enterprise server 15 SP7
8.14.1-150700.7.20.1
fixed
Amazon Linux logo
Amazon Linux Releases
Amazon Package
Release
curl
Amazon Linux 2023
0:8.21.0-5.amzn2023.0.1
fixed
curl-debuginfo
Amazon Linux 2023
0:8.21.0-5.amzn2023.0.1
fixed
curl-debugsource
Amazon Linux 2023
0:8.21.0-5.amzn2023.0.1
fixed
curl-minimal
Amazon Linux 2023
0:8.21.0-5.amzn2023.0.1
fixed
curl-minimal-debuginfo
Amazon Linux 2023
0:8.21.0-5.amzn2023.0.1
fixed
libcurl
Amazon Linux 2023
0:8.21.0-5.amzn2023.0.1
fixed
libcurl-debuginfo
Amazon Linux 2023
0:8.21.0-5.amzn2023.0.1
fixed
libcurl-devel
Amazon Linux 2023
0:8.21.0-5.amzn2023.0.1
fixed
libcurl-minimal
Amazon Linux 2023
0:8.21.0-5.amzn2023.0.1
fixed
libcurl-minimal-debuginfo
Amazon Linux 2023
0:8.21.0-5.amzn2023.0.1
fixed